Keep the dockwidget with the mouse when moving to another screen

When you move a dockwidget from one screen to another then it needs to
be kept at the same position on the new screen, i.e. with the mouse
pointer. This fix ensures that this is happening including when the
screens may not 100% align up with each other.

Task-number: QTBUG-33369

Change-Id: If414effdd0e0415629ca31a86f8bbe382dd29f80
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@digia.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/src/plugins/platforms/cocoa/qcocoahelpers.mm b/src/plugins/platforms/cocoa/qcocoahelpers.mm
index 197a2058af..4a5696b35e 100644
--- a/src/plugins/platforms/cocoa/qcocoahelpers.mm
+++ b/src/plugins/platforms/cocoa/qcocoahelpers.mm
@@ -599,7 +599,17 @@ NSRect qt_mac_flipRect(const QRect &rect, QWindow *window)
 {
     QPlatformScreen *onScreen = QPlatformScreen::platformScreenForWindow(window);
     int flippedY = onScreen->geometry().height() - (rect.y() + rect.height());
-
+    QList<QScreen *> screens = QGuiApplication::screens();
+    if (screens.size() > 1) {
+        int height = 0;
+        foreach (QScreen *scr, screens)
+            height = qMax(height, scr->size().height());
+        int difference = height - onScreen->geometry().height();
+        if (difference > 0)
+            flippedY += difference;
+        else
+            flippedY -= difference;
+    }
     // In case of automatic positioning, try to put as much of the window onscreen as possible.
     if (window->isTopLevel() && qt_window_private(const_cast<QWindow*>(window))->positionAutomatic && flippedY < 0)
         flippedY = onScreen->geometry().height() - onScreen->availableGeometry().height() - onScreen->availableGeometry().y();